Studies suggest that characteristics of the environment are encoded as part of the memory trace, and can be used to enhance retrieval of the other information in the trace. In other words, you can recall more when the environments are similar in both the learning (encoding) and recall phases. Thus, deep-sea divers tend to remember their training more effectively when trained underwater rather than on land, and students perform better on exams by studying in silence, because exams are usually done in silence. You might mention this the next time you see your child studying for a test with earbuds in their ears!